In the era of modern water law, tribes have buttressed their water rights by drawing on a 1908 Supreme Court opinion in a case involving the use of the Milk River in north central Montana. In that case, Winters v. US, the court found that when the federal government created the Fort Belknap reservation it implicitly reserved the rights to use a sufficient amount of the river’s water to fulfill the purposes of the reservation as a homeland for the Gros Ventre and Assiniboine people.
These “Winters doctrine” rights, now applied to tribes in Arizona and across the country, have a number of distinctive aspects to them.
● The rights are considered as having been established as of the date the federal government created the reservation involved. This means that tribal rights are nearly always senior to those of most other current users of Western water.
● The rights cannot be forfeited by non-use, as can the rights held under state law according to the principle of “prior appropriation.”
● Although the scope of these rights is sometimes quantified as being the amount of water necessary to support the “practically irrigable acreage” on a reservation, the rights, once quantified, can be used for non-agricultural purposes.
● The rights involve the future needs on a reservation, not just the present needs.
The “Winters doctrine” and the specifics derived from it in case law and in federal legislation form the basis of the water rights of the tribes in Arizona.
Click here for the US Supreme Court decision in the Winters case. http://supreme.justia.com/us/207/564/case.html